1883 - Birth of Heinrich Mathy, one of the most daring and audacious Zeppelin raiders of WWI.
1884 - Birth of Isoroku Yamamoto, Japanese Naval Marshal General and the commander-in-chief of the Combined Fleet during WWII, responsible for a number of innovations in Japanese naval aviation.
1885 - Birth of Hans Klemm, German aircraft manufacturer noteworthy for sports and touring planes of the 1930s.
1891 - Birth of William James Alexander Weir, Australian WWI flying ace
http://en.wikipedia.org/wiki/William_Weir_(aviator) - http://www.theaerodrome.com/aces/australi/weir.php
1893 - Birth of Frederick Joseph "Fred" Noonan, American flight navigator, sea captain and aviation pioneer.
1896 - Birth of Harold Robert Buckley, American WWI flying ace and author.
1900 - Birth of João Ribeiro de Barros, 1st aviator of the three Americas to make an air crossing from Europe to America.
1907 – Santos-Dumont makes a short flight of 164 feet with his XIV-bis in Saint-Cyr, France.
1913 - Death of Emmanouil Argyropoulos, Greek pioneer aviator, in a captured Ottoman Blériot XI during the Balkan war. Apart from being the first Greek aviator who performed a flight over his homeland, he also became the 1st casualty of Greek military aviation
1913 - Mexicans Miguel Lebrija Urtetegui and Juan Guillermo Lopez Villasana simulates a Bombing raid with a Deperdussin over Babuena Airport with Martin Hale Bombs.
1917 - 1st flight of The SPAD S.XIII, French biplane fighter aircraft, one of the most capable fighters of WWI, and one of the most-produced, with 8,472 built and orders for around 10,000 more cancelled at the Armistice.
1918 - Death of Kurt Gruber, Austro-Hungarian Imperial and Royal Aviation Troops WWI flying ace, Killed in action in his Phönix D.I.
http://it.wikipedia.org/wiki/Kurt_Gruber_(aviatore) - http://www.theaerodrome.com/aces/austrhun/gruber.php
1918 - Death of Heinrich Georg Geigl, German WWI fighter ace, colliding with a Sopwith Camel in his Fokker DRI.
1918 - In early attempts at naval aviation, A Sopwith 1½ Strutter is launched from HMAS Australia 'Q' turret.
1922 - Death of Paul Ward Beck, American aviation pioneer, and one of the 1st military pilots.
1922 - The Colombian Ministry of War opens a flying school (the Escuela de Aviación) at Flandes.
1924 - 4 Douglas World Cruisers of the U.S. Army Air Service takes off from Santa Monica, California, for Sand Point, Washington, near Seattle, for what will be the 1st aerial circumnavigation of the world.
1925 - Birth of Serge Dassault, (son of Marcel Dassault, from whom he inherited the Dassault Group.) French entrepreneur (Chairman and Chief Executive Officer of Dassault Group) and conservative politician
1928 - 1st flight of the SPCA 10, French parasol wing 5 seat 3 engine patrol flying boat prototype.
1933 - US Navy airship USS Akron crashes during a storm, killing 76 of its 79 crew, Including William Adger Moffett, American pilot, admiral, architect of naval aviation in the United States Navy, known as the "Air Admiral".
1938 - The sole LACAB GR.8, prototype Belgian multi-role combat aircraft, crash-landed with its undercarriage and starboard wings destroyed. Although the aircraft was repaired, it was not flown again, and no production was undertaken.
1938 - 1st flight of the Breguet 730-01, French 4 engine high wing flying boat prototype.
1939 - Death of Joaquín García-Morato y Castaño, 1st Count of Jarama, leading Nationalist fighter ace of the Spanish Civil War, he was performing low aerobatics for newsreel cameras, when his Fiat CR.32 crashed
http://en.wikipedia.org/wiki/Joaqu%C3%ADn_Garc%C3%ADa_Morato - http://surfcity.kund.dalnet.se/spain_morato.htm
1942 - S/L L.J. Birchall and crew sighted a Japanese flotilla 350 miles south of Ceylon. Thereafter he was known as the Saviour of Ceylon. He was shot down and taken prisoner.
1944 - 1st bombardment of Bucharest by Anglo-American against railroad targets ends due to strong winds that deflected bombs in the death of 3000 civilians.
1945 - Death of Heinrich Ehrler, German WWII fighter ace, ramming in a B-24 with his me-262.
http://en.wikipedia.org/wiki/Heinrich_Ehrler - http://www.cieldegloire.com/001_ehrler_h.php - http://www.luftwaffe.cz/ehrler.html
1947 - The International Civil Aviation Organization (ICAO) is officially founded in Montreal, Canada. It is an intergovernmental organization, established to regulate air transportation on a worldwide basis, its authority restricted only by the number of signatory nations.
1947 - William P.A. 'Bill' Straith, Early Canadian Aviator, Aircraft designer and airline manager is killed while flying a company AT-6 aircraft at Raton, New Mexico, probably due to anoxia from flying at high altitude without oxygen.
1948 - Death of Frank Searle, British transport entrepreneur, a locomotive engineer who moved from steam to omnibuses, the motor industry and airlines
1949 - NATO, system of collective defence whereby its member states agree to mutual defense in response to an attack by any external party, is formed.
1947 - One of Canada's 1st TCA pilots Bill Straith is killed in an accident in New Mexico.
1950 - 1st Flight of The PZL-Swidnik BZ-1 "Gil", 1st Polish experimental helicopter.
1950 - 1st flight of The Jodel D11, French two-seat monoplane designed and developed by Société Avions Jodel in response to a French government request for a low-wing aircraft for use by the nation's many emerging flying clubs.
1950 - Squadron Leader Janusz Zurakowski flies a Gloster Meteor jet fighter from Northolt to Kastrup Airport in Copenhagen in 1 hour 5 minutes and makes the return journey on the same day in 1 hour 11 minutes
1952 - French test pilot Claude Legrand and mechanic Lavigne are killed in the crash of a Fouga CM-71 glider, as it encountered flutters during a fast low pass causing the glider to break in midair.
1956 - 1st flight of the Grumman F9F-8T Cougar, aircraft carrier-based fighter in a 2 seats training version.
1957 - 1st Flight of The 2nd prototype English Electric Lightning P1B, British supersonic jet fighter aircraft. (Single-seat operational prototype to meet Specification F23/49.)
1957 - CIA Stealh prototype Lockheed U-2 (Wallpaper equipped) crashed. The heat buildup caused the engine to stall. Without power to maintain cockpit pressurization, the faceplate on Robert 'Bob' Sieker's helmet popped open and he lost consciousness. Uncontrolled, the U-2 went into a flat spin. Sieker recovered and bailed out, but at too low an altitude and he was killed.
1964 - Birth of Satoshi Furukawa, Japanese surgeon and a JAXA astronaut.
1968 - Flight of Apollo 6, 2nd and last A type mission—unmanned test flight of its Saturn V launch vehicle. 10 hours after launch, it landed 43 nautical miles (80 km) from the planned touchdown point, and was lifted on board the USS Okinawa.
1975 – Operation Baby Lift – A USAF C-5A Galaxy crashes near Saigon, South Vietnam shortly after takeoff, transporting orphans – 172 die.
1977 - Southern Airways Flight 242 Douglas DC-9-31 executed a forced landing on a highway in New Hope, Paulding County, Georgia, after suffering hail damage and losing thrust on both engines in a severe thunderstorm. During the rollout the aircraft collided with a gas station/grocery store and other structures : 63 over 85 were killed plus 9 on ground.
1983 - Launch of STS-6, 6th space shuttle mission and the 1st of the ten missions flown on Challenger.This was the 1st mission the Extravehicular Mobility Unit was used.
1984 - Death of Oleg Konstantinovich Antonov, Soviet aircraft designer, the founder of Antonov ASTC, a world-famous aircraft company in Ukraine, later named in his honour.
1984 - 1st flight of The Bell 400 TwinRanger, American prototype four-bladed, twin-engine civil helicopter.
1987 - Garuda Indonesia Flight 035 Douglas DC-9-32 struck a pylon and crashed on approach to Medan-Polonia Airport in bad weather, killing 23 over 45.
1991 – Senator John Heinz of Pennsylvania and six others are killed when a Bell 412 helicopter collided with the Senator's Piper Aerostar plane over an elementary school in Merion, Pennsylvania.
1993 - 1st flight of The Fokker 70, narrow-body, twin-engine, medium-range, jet airliner.
1995 - Russian Air Force warplanes are deployed to support the mobilisation of troops into Chechnia
1996 - Death of Boone Tarleton Guyton, Naval Aviation Cadet, WWII pilot, experimental test pilot, author and businessman. In a flying career spanning the biplane era through the jet age, Guyton was perhaps best known for his test pilot years at Vought-Sikorsky (Chance Vought) and his participation in the development of the F4U Corsair and various other military aircraft including the OS2U Kingfisher and the radical Vought V-173 flying pancake.
1997 - Launch of STS-83, American Space Shuttle Columbia mission.
2000 - Launch of Soyuz TM-30, 1st privately funded manned space expedition.
2000 - Death of Rolf Pingel, German fighter ace of the Spanish war and WWII.
http://en.wikipedia.org/wiki/Rolf_Pingel - http://www.luftwaffe.cz/pingel.html - http://cieldegloire.com/001_pingel_r.php
2010 - 3 minutes ahead of schedule, Soyuz TMA-18 successfully docked to the Poisk module on the ISS.
2011 - Launch of Soyuz TMA-21 "Gagarin", Russian Soyuz flight to the International Space Station (ISS)
2011 - A United Nation flight UNO834 Canadair CL-600-2B19 Regional Jet CRJ-100ER crashed near Kinshasa-N'Djili Airport in rainy weather killing 32 over 33.
http://en.wikipedia.org/wiki/2011_United_Nations_Bombardier_CRJ-100_crash - http://aviation-safety.net/database/record.php?id=20110404-0
2013 - 1st flight of the Pipistrel 'Panthera', Slovenian low wing 4 seat tourer aircraft.